I've confirmed my answer.
I extracted the TBSCertificate, signatureAlgorithm, and signature from the subject certificate and then parsed the signatureAlgorithm to determine the hash algorithm to use (it was SHA-1).
Then, I extracted the public key from the CA certificate.
Then, I built the public key token using CSNDPKB.
Then, I called CSNDDSV with
rule_array = 'RSA '||'MESSAGE '||'SHA-1 '||'PKCS-1.1';
data = tbsCertificate;
sig_field = signature;
to verify the certificate.
In your example, that would be 30 82 03 5B plus the next 0x035B bytes of data.